jacques



(No Model.)

W. W. JACQUES.

TELEPHONE EXCHANGE SYSTEM.

No. 263,524. Patented Aug. 29, 1882.

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UNTTED STATES PATENT @FFIQE.

WILLIAM W'. JACQUES, CF BOSTON, MASSACHUSETTS, ASSIGNOE TO THE AMERICAN BELL TELEPHONE COMPANY, OF SAME PLACE.

TELEPHONE-EXCHANGE SYSTEM.

SPECIFICATION forming part of Letters Patent No. 263,524, dated August 29, 188.2.

Application filed May 23. 1882. (No model.)

' Boston, in the county of Sufi'olk and State of Massachusetts, haveinvented certain Improvements in Telephone-Exchange Systems, of which the following is a specification.

My invention relates to a method or" and,

apparatus for effecting electrical intercommunication, known generally as the telephone district or exchange system. It is well known that such an organization consists of a central station, a number of substations, line-wires radiating from the central station and connecting it with the several substations, communicating-instruinents at each sub-station, and suitable signaling and switching appliances at the central station, whereby any two of the sub-stations may be'placed at a moments notice in direct electrical communication with one another through the instrumentality of the attendant at the central station, who, when notified to do so, connects together the two lines leading to the respective sub-stations, so that they are thereafter enabled to comm unicate with each other directly.

Experience has demonstrated that when several line-wires used in the transmission or conveyance of electricity for arious purposes are stretched in parallelism to one another,

some ofthein being furnished with telephones and employed in the transmission and reproduction of articulate speech, any variation of the electric force in any of the wires affects the telephone-lines adversely and reproduces in thetelephones attached to such lines the signals which may be passing in any or all of the other lines, to the detriment of conversation,upon thetelephone-linesthemselves; and,

. also, that when two or more separate telephonelines are supported or laid in close proximity to one another for a considerable distance the articulate speech transmitted upon one line is reproduced on the others by induction or without actual contact ofthe several lines involved. 'Io counteract this detect it has been proposed to provide for each line a parallel return-wire, thus making a metallic cii cuit, so that the foreign currents induced in one wire of such a metallic circuit will be neutralized by the. same current flowing in the oppositedirectiou in the other wire of the circuit, and by such neutralization dispense with the extraneous signals; but in a telephone-exchange system it is both impracticable and inconvenient to construct all of the line-circuits with a metallic instead of an earth return, and many circuits must then, as heretofore, terminate at the earth, both at the central and sub stations; and it has been found difficult to construct apparatus at such stations whereby metallic circuits can be 0011- veniently adapted for cross or interconnection with single or ground circuits without losing the advantage gained by the metallic form, inasmuch as it a single line be caused to make contact with a loop it has the effect of reducing that loop virtually to a similar singlcline, unless special arrangements are devised for this contingency; and to this end the object of my invention is the convenient arrangement of specific apparatus at the several sub-stations and at the central station with reference to the connecting-lines, so that ina mixed system, consisting, as I have hereinbefore indicated, partly of metallic circuits and partly of grounded circuits, the interconnection of any two metallic circuits, or of any two single or grounded circuits. or of a metallic circuit With a grounded circuit, may be readily and rapidly effected without necessitating the use of complex apparatus or the performance of intricate and multitudinous operations.

My invention consists, first, in the combination' of a central-station switch-hoard having two series of conducting bars or strips arranged in pairs thereon transversely to one another, a series of telephone-lines, part of which are metallic and part earth return-circuits, radiating therefrom to a corresponding series of substations, and signaling apparatus of a simple characterat the several sub-stations connected with each metallic circuit, by which the central station may signal the sub-station upon one wire of the metallic circuit and the sub-station may communicate with the central station by means of the other wire of the metallic circuit, while, when the circuit is connected with another similar circuit through the apparatus at the central station, both wires are utilized in the act of intercoinmunication by being temporarily formed into a complete metallic or ring circuit between the two sub-stations connected; 0r,if one of the two be located upon a single IOC or earth return-circuit,an additional earth-wire is caused to take the place of the metal return, in a manner specifically hereinafter described.

It also consists in the combination, with a central station and a series of sub-stations, of a douhleline wire extending between the said central station and each of the sub-stations, and connected with the apparatus at either terminal in such a manner that one wire of the said double line is normally connected through the signaling-instrutneut to earth at the substation, remaining open or insulated at the central station, while the other is connected through telephones or other signaling-instrument to earth at the central station and is normally open at the sub-station.

It further consists in the combination of the double line with an instrument at the sub-stations adapted to normally maintain one wire of the said double line in connection with the signaling apparatus and the earth and the other wire open, or, when manually operated, to couple the said wires together as a loop, including the sub-station telephone, and with comm utating apparatus at the central station, whereby the two ends of the said double line may be electrically connected with the corresponding ends of a similar double line extending to another sub-station, or with a single line and a ground-wire.

In theaccotnpanyingdrawings is represented, in Figure 1, a theoretical diagram, showing a general arrangement of my improved system; and Fig. 2 is a sectional view of the device for making the connections at the central-station switch.

In the drawings, 0 is a switch-board at the central station, and is provided with a series of vertical conducting-strips, d to (1 inclusive. In front of these, and crossing them transversely, but insulated therefrom, is a series of horizontalconduct.ing-strips,eta. Both series are arranged in pairs, and the vertical strips are permanently connected with the wires of a series of line-circuits, I, I 1 I, 1 and I. With the exception of I and 1", these wires all extend in parallel pairs to sub-stations S S S S The line-wire 1 extends as a single wire to ground at a sub-station; but at the central station, A, it is connected in the switch-board G in precisely the same manner as the terminals of the double or metallic circuits are, occupying, as they do, a pair of vertical switch-strips, d and d. The wire 1 leaving the switch-bar d is connected with the ground at the central station.

I have in the drawings shown but one earth return-circuit combined with a series of metallic circuits; but it is well understood that any number of such circuits may readily be arranged on the same plan. I provide a double plug-connector, 1), for each line-circuit, and the plugs or connectors may be constructed as shown in section in Fig. 2, and are formed of 5 two metallic pins,fand f, completely insulated from one another, yet held mechanically together by the plate of non-conducting material e, in the middle of which is inserted the handle 19.

dand drepresent sections of the vertical bars of the switch-board, and a is a portion of a horizontalbar. AsshowninFig.1,themetallicbars of each series are perforated at each intersection with holes for the reception of the plugs p. These holes extend through both horizontal and vertical strips, so that a pin or plug of metal inserted in any of the holes will connect together metallically at the point of intersection the horizontal and vertical bars through which it is thrust. In Fig. 2 the section is taken through the center ot'the hole of the lefthand vertical strip (1 and just above the hole in the right-hand strip d. At the lower edge ofthe switch-board O are three horizontal bars, a, c, and 0 also crossing the vertical bars, and perforated, as are the connection-bars (I, for the reception of the plugs. The middle bar of the three, 0, is permanently connected by the wire it with the transmitter D and telephone E, and thence to earth at G. The upper and lower bars of the three, 0 and 0 are insulated, and serve merely as supports or sockets for the unoccupied leg of the plug 1). All the plugconnectors ot' the metallic or two'wire circuits are normally placed in the position shown in the drawings as occupied by those of circuits 1. and 4, while the plugs of single or ground return-circuits are normally placed in the position occupied by that of circuit No. 5. Thus each circuit is normally connected at the central station with the transmitter D and the receiver E, the two-wire circuits by the wires to passing through the switch-board by the right-hand bar of each pair, and the horizontal bar 0, and the single-line circuits by their only line-wire entering the switch-board by the left-hand vertical bar of each pair.

It will be seen from the foregoing description that the plugs of the metallic circuits are invariably placed when at rest on the crossbars 0 and c, and the plugs of the single or grounded circuits are under the same conditions placed on the cross-bars c and 0 It is obvious that by this arrangement the metallic circuits can be readily distinguished from the grounded circuits by means of the higher level on the switch-board at which their plugs are normally placed. Immediatelyabove the three strips 0 c c are two other horizontal conducting-bars, b b. The upper bar, I), of this pair is permanently attached to a wire, g, leading to a battery or other source of electricity, l, through a circuit-closing key, k, and the lower bar, b, is insulated, serving only the same purpose as the bars 0 and e in the lower series viz., to support the unoccupied leg ot'the plugcounector.

I may, if I so elect, dispense with the key.

and connect the battery directly with the bar I); or I may insert in lieu of or in addition to the said key a pole-changer or current-reverser. I may also use any form of magneto-electric generator in place of the battery I, it I find it advisable so to do.

The plugs p of circuits 2 and 3 are represented as being placed upon the same pair of horizontal plugs, a a, thus connecting their respective line-circuits together for oral intercommunication.

The instrumcntalities at each of the metallic-circuit sub-stations S S S S are identical in character and operation, each one being a duplicate of the others. Such being the case I have shown but one-that one at station S.

The apparatus used at the sub-stations connected with the single or earth return-circuits may be of any desired character, and therefore, forming no part of my invention, need not here be particularly described.

I will now describe the apparatus at the station S. It consists of a base-board, B, upon which is supported a signaling-bell, an, a telephone-transmitter, O, and a pair of keys, n and 0. A receiving-telephone, T, is also provided, which may, when not in use, he placed wherever desired. The key a is a strap-key, and when pressed makes contact with two contactpieces, 8 and s. The key 0, also a strap-key, is also provided with two contact-pieces, t and t, with which it makes contact when pressed, and has in additionto these a bridge-piece, 'r, forming a back contact or limit, against which, when at rest, it presses by its own resiliency. As herein before indicated, one of the two wires connecting the sub-station with the central station is normally open at the latter point. This wire 20 is at the central station connected with theleft-hand verticalstripofanypair, from which it extends outward till, reachingthe substation S, it enters the apparatus at a bindingscrew, makes permanent connection with the key '0, and by means of the bridge or back contact 1' and wire to it reaches one terminal of the hell-magnetm, and,passingthrough the magnet mand wirew, terminates atthe ground G,form ing a line between the central station and the sub-station, normally open at the former and closed to earth at the latter after passing through the bell-magnet coils. This wire is used alone when the central station desires to signal the sub-station, and when this operation is to be performed the plug 1) is taken from its normal position on the horizontal bars 0 and placed on the bars b b, as indicated by the dotted lines, circuit 1. This operation opens wire to and connects wire to with the crossbar I), and this being electrically connected with the wire 9 and key It, when the said key is pressed the circuit of the battery lis closed to line, and its current, traversing the wire L0, causes the bell m to ring, giving the signal. The second wire of each pair, to, is in diametrical opposition to the first, normally open at the sub-station, and closed at the central station. Entering the central station, the wire 10 is attached to the right-hand bar dot' its pair. This bar, by means of the plug 19, is normally connected with the cross-bar c, and by the wire h and through the telephonic transmitter D and receiver E to earth. Its course, after leaving the central station, is over wire 10 till it arrives at the sub-station S, thence through telephone '1, secondary coil of transmitter (J,

thence to the main stem of strap-key a, when it is normally open. When communication with the central office is desired the subscriber presses the key a, causing it to make contact with the two contactpieces s and s. The contact of the key a with the contact-piece .9 completes the circuit of the telephone-wire w to earth, and the contact of the same key with the piece 8 closes the circuit of the transmitterbattery to through wire a, primarycoil of transmitter 0, wire a, key a, contact 8, wire 10 and wire to back to the other pole of the battery. The transmitter O is vitalized by the closing of the battery a, and the subscriber, continuing to press the key a, speaks into the transmitter and gives his order for connection with the desired sub-station. The central-station attendant or operator, who is presumed to be constantly listening for calls at the telephone E, responds tothe call and takes the order. making the necessary circuit-changes. The left-hand contact-piece t of the key 0 is connected by the wire to with the key a, while the right-hand contact-piece t is connected with an extension of the local-battery wire to. When the key 0 is pressed the following disposition of circuits is made. The wire w is severed from its normal continuation through the bell m, and is by means of the key 0, contact 23, and wire 10 connected with the open end of the wire to, the two wires to and 20 thus forming a temporary loop,which includes the sub-station telephones, and the primary or battery circuit is closed by the contact made between the two contactpieces t and t across the metal of the key 0. Hence the transmitter G is vitalized by the closing of its battery-circuit whenever either key is depressed.

The line as then constituted between the central and sub station is traced from the pointd at the switch-board over line-wire to, key 0, contact t, key a, secondary coil of transmitter G, by wire 20 out by wire to" to telephone T, thence by wire to back to the central station at (1. Here it is capable of connection with a similarloop-circuit, l -tor example, by placing the plugs of each of two circuits to be connected upon the same pair of horizontal bars, a and a, as shown in circuits 2 and 3, which are thus connected. The circuit from (1 continued down 'ard by the vertical bar, is connected by the plug p with the cross-barato theleft-hand bar d of circuit 3, thence over the wire to the sub-station, back to the central station by the parallel wire to right-hand switch-bard, downward to plugp and cross-bar a, thence to lefthand bar d ot circuit 2, over the line to substation S, and back by parallel wire again to 01 and the two stations, when talking to one another, will be connected byacontinuous metallic or ring circuit consisting of two pairs of. vertical switch-bars, one pair of horizontal switch-bars, a parallel pair of line-wires to each sub-station, and at the sub-stations the key 0 and contact tjoining the normally separated IIS ends of the two wires. By the use of the ringcircuit the etfects ot' inductive interference, which are otherwise troublesome, are eliminated.

To effect the same result where a double line is to be connected with a single line and obtain for such a combination all the ad vantage resulting from a ringcircnit, I have shown such a circuit starting from the earth at substation S, proceeding over the single line 1 switch-board bar (1 plug 2), to a normal connection through the ccntra-l-otiice telephones to earth. Any preferred form ofstation apparat us may he used in connection with the said line I at the sub-station S The parallel bar ('1 is permanently connected at the central office with the grountlwvire i and at its lower end is noimally insulated; but when the circuitis to be connected with a metallic circuitfor example, with No. 2the plugs of both circuits are placed upon the same pair of parallel bars, a a. This brings into operation the parallel strip d and its groulid-connection and places the circuit No. 5 in a position to beeonnected with the metallic circuit No. 2 upon equal terms. When so connected the compound circuit, staitingfroui the eaith at substation S is over wire 1", switch-bar (i plug p, crossbar a, plug 12, switch-bar (1 line i to sub-station S, back by parallel wire to switch-bar d and wire I, to ground at central station. In operation this method of working is as follows: S wants to talk with S. lle presses key a. This completes the talking-circuit wire 20 and closes the local circuit. He then says S wants S. The operator listening at the telephone E at central ol'lice repeats the order, and then puts the plug of 2 on the battery-bars I) b and presses his key 7:. This sends electrical currents over the wire Q0 of circuits 2 to the substation S and rings the bell there. The respective. plugs 17 of circuits 1 and 2 are then both placed on the same pair of strips, a to. Both sub station operators press their key 0 and converse.

I claim as my invention-- 1. In a telepbone-exchange system, a central station, a series of sub-stations, aserics of lines extending between the central stations and each of a portion of the substations, each line of the series consisting of two parallel wires, a series of single line-wires extending between thecentralstationandothersubstationsaneans at the central station whereby any of the pairs of linewires may be connected as a. loop with any other pair or with any single line, means at the several sub-stations connected with the paired lines whereby signals may be received upon one wire or transmitted upon the other, and connecting devices at the sub-stations whereby the two terminals of the said parallel wires may be connected together to form a metallic loop including the sub-station telephones, all in combination, and substantially as described.

2. Thccombinatioinin a telephoneexchange systemsubstantially t s hereinbet'ore descri bed,

of a central station, sub-stations, two linewires extending between the central station and each sub-station, parallel with butnormally separated and insulated from one another, one of the said wires being normally adapted by means of devices controlled by the central station for the transmission of alarm-signals to the sub-stations, and the other being normally adapted for the transmission of articulate speech between theeent -al and sub stations by means of devices at the sub-stationscontrolling such tninsmission, separate devices at the substations adapted to connect the parallel wires together in a continuous loop, a single-line and ground wire, and switching devices at the central station t'or connecting the parallel wires from any substation with those of any other pair or with said singleline and ground wire, for the purposes set forth.

3. In a tele thone-exchange system, the combination of a central station and a sub-station or series thereof, line-wires in pairs extending between thecentralstationandthesubstatious, signal-receiving devices at the sub-station and signal-transmitting devices at the central station connected with one wire of each pair, and telcphonicins .ruments at both termini, but under the control of the sub-station connected with the other wire of each pair, whereby the sul -station is signaled over one wire exclusively and articulate speech between the central station and the sub-station is maintained over the other wire, a circuit-changer at the sub-station adapted to sever the signalwvire from the signal-receiving devices and connect it with the telephone-wire to form a loop, and switching devices at the central station adapted to connect the ends of the said loop with the ends of any other loop, or with a single-line wire and a ground-wire, as described, and for the purposes set forth.

4. In a telephone exchange system, the combination of a series of subscribers lines, consisting in part of metallic or looped circuits and in part of single or earth return-circuits, with a cent: al-station switch-board constructed, substantially as described, with intersecting vertical and horizontal conducting-bars and double connectors adapted to connect by one motion any pair of vertical bars to any pair of horizontal bars at theintersecting point, and circuit-changing apparatus at the substations located on the line of the metallic circuits, whereby the two lines composing the metallic circuit are operated separately or as one circuit, for the purpose specified.

in a system of telephonic communication, the combination, substantially as hereinbefore described, of a switch-board having its line and connecting bars or strips arranged in pairs and provided with double plug-connectors, one for each circuit, circuit-wires extending in pairs from the said switch-board to a series of substations, one wire of each pair being normally open at the central station and closed at the sub-station and the other closed at the central station and open at the sub-station, and

circuit-chan gin g apparatus at the said sub-stations adapted to connect the ends of the two circuit-wires and form thereof alooped circuit including the sub-station telephones, substantially as described.

6. A line-wire extending between a central station and a sub-station, normally open at the central station and closed through a signalingiustrument at the sub-station, signaling devices at the central station, and means for connecting the open end of said line-wire'with said signaling devices, combined with a second line-wire extended ,in parallelism to the first, but normally separate and insulated therefrom, and connected with telephones and the earth at the central station, but open at the sub-station, and means for connecting the open terminal of the second line-wire, through the sub-station telephones, with the earth or in metallic circuit with the first wire, substantially as and for the purpose specified.

7. The combination, at a sub-station of a telephone exchange system, of a mainline having in its circuit the sub-station telephone or telephones, and terminating in two normallyopen branches, with a second main line normally connected with a branch circuit to earth through a signalinstrument, and means, as

indicated, whereby it is severed from the said branch circuit and transferred to one of the open branches of the first main line, substantially as described.

8. The combination, at asub-station ofa telephone-exchange system, of a main line extending from the central station, having in its circuit thesub-station telephones, and terminating in two normally-open branches, one of which is a key, a second main line, also extending from the central station and normally connect-- ed with abranch circuit to earth through a signal-instrument, a local-battery circuit normally open, and circuit-changing keys, one for each Wire, whereby when one of the said keys is pressed the main line through the telephones is closed to earth and thelocal-battery circuit completed, and when the other key is pressed the two lines are connected together as a loop, substantially as described.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this 13th day of May, 1882.

W. \V. JACQUES.

Witnesses:

J. H. GHEEVER, GEo. WILLIS Prnacn. 

